Pressed to name a foreign leader that he admires, during a televised interview on Wednesday, the Libertarian Party presidential candidate struggled to supply a name of a single one, sheepishly alluding to another moment of embarrassment from earlier this month.

Mr. Johnson, a former governor of New Mexico, was eventually able to land upon a position – the former president of Mexico – though he was unable to match it to a name – Vicente Fox – until his running mate, former governor of Massachusetts, Bill Weld, supplied it.

The lapse, like the “Aleppo moment,” in which Johnson "blanked" on a city central to the conflict in Syria -- the candidate says he assumed it was an acronym -- illustrates the candidate’s glaring lack of expertise regarding the world beyond the United States’ borders, and perhaps even his lack of interest. But it may also underscore the source of his appeal among young people, who make up his core supporters.

In a mid-September poll conducted by Quinnipiac, 29 percent of likely voters between 18-34 said they would cast a ballot for Johnson. That’s better than Republican nominee Donald Trump’s 26 percent and slightly behind Democratic candidate Hillary Clinton’s 31 percent.

It isn’t that foreign policy doesn’t matter to young voters, although older people do place slightly more importance on it. This July, the Pew Research Center found that 70 percent of 18- to 29-year-olds saw foreign policy as “very important” to their vote. And it wasn’t much less than for 30- to 49-year-olds (72 percent) or 50- to 64-year-olds (77 percent).

But the young also tend to view foreign policy differently. A 2015 study by the libertarian Cato Institute concluded that Millennials – defined here as those born between 1980 and 1997 – see the world as “significantly less threatening than their elders,” and policies drawn up to deal with foreign threats as less urgent. They’re also more supportive of international cooperation, and far less keen on the use of military force, the report found.

Both major candidates are considerably more hawkish than this standard. In comparison, Johnson’s floundering on foreign policy questions might seem relatively benign.

Days after his original "Aleppo moment", Mother Jones reported that at a rally for the candidate held in New York, some of his supporters cited Johnson’s demeanor – the absence of rancor toward other candidates or appeals to voters’ fears – as a reason for their vote, dismissing his flub as unimportant.